Known field-bus connecting devices hold, in an essentially square housing, a motherboard which is supported on the base. On one side of the housing, a plurality of connection elements is permanently connected to the housing, by means of which connection elements the sensors and actuators and the serial bus system can be connected to the motherboard. There are various connection techniques for connecting the sensors and actuators and the serial bus system to the housing, the connection elements being embodied, for example, as cable bushing connectors, plug-type connectors or plug-type/screw-type connectors. However, because the respective connection elements are permanently connected to the housing, such field-bus connecting devices have the disadvantage that the respective connection technique is fixed for each housing, and that in the event of defects in one or more connection elements the entire field-bus connecting device has to be replaced.
German Offenlegungsschrift DE 44 37 316 A1 discloses a field-bus connecting device in which a plurality of connection elements can be connected to a motherboard which is embodied as a signal processing device and which is arranged in a square housing. In each case a plurality of connection elements are arranged in a module here, the modules having plug-type connectors for plugging onto mating plug-type connectors which are provided on the motherboard, that is to say they can be replaced individually.
In such a field-bus connecting device, the modules can indeed each be replaced individually, but the motherboard with the associated electronics is then freely accessible from the outside, entailing the risk of the electronics being damaged or tampered with by the user. Furthermore, the configuration of the modules is largely prescribed for each module location on the motherboard, with the result that different connection techniques cannot be combined as desired.
German Offenlegungsschrift DE 39 33 099 A1 discloses a modular assembly and wiring system in which a plurality of housings with inserted modules which are locked by means of securing latches are plugged onto an insulated busboard. Owing to the fact that the modules are closed, it is not possible to replace different connection elements as desired. In addition, the busboard is also freely accessible in this device when the modules are being replaced.
German patent DE 197 16 137 C1 and German utility model DE 296 07 525 U 1 each disclose connecting devices for connecting actuators and/or sensors which have one or more upper parts which can be fitted onto a lower part and have a plurality of connection elements for the sensors and actuators. In addition, German Offenlegungsschrift DE 196 15 093 A1 discloses a serial interface for field buses which has an automation unit with a communications adapter which can be plugged onto a plug-type connector. There is no provision for different connection techniques to be implemented by replacing individual connections in these devices, nor is this possible.
Finally, German patent DE 44 12 270 C2 discloses a decentralized interface module for a bus system in which the electronic control unit can be assembled with differently equipped connection fittings in order to adapt it to different connection techniques. However, the control electronics are inevitably freely accessible here and thus exposed to the risk of damage or tampering.